Demonstrating Construction Quality

What you need to know

Demonstrating construction quality.

Either:-

Use only accredited robust construction details.
Robust Standard Details (RSD) are still applicable although not yet updated; and where RSDs are not followed, there are more rigorous air pressure tests required, in as much as the air pressure test must comply with permeability levels as well as complying with the figures that have been factored in to the TER.
Must provide schedule of details and evidence of appropriate site inspections by suitably qualified person. Must also provide pressure test for one dwelling form first batch of each type, to demonstrate compliance with the air permeability standard in including the DER

Or:-

Carry out pre-completion testing
Air pressure testing compliance will follow the recommendations of the Air Tightness Testing and Measurement Association's “Measuring Air Permeability of Building Envelopes.” Those not using RSD must test two units of dwelling type per development, or 5 percent of each dwelling type overall. The dispensation for small developers has altered and now if the development is of fewer than five units then only one test per building type will be deemed to satisfy. If relying on calculations, the dispensation allows for an air permeability value of 15m³/hm² at 50Pa to be factored into the TER to provide a suitable contingency.
Must provide pressure tests of either two dwellings of each type or 5% of each dwelling type in the development (whichever is greater), form the first 25% of each type complete, to demonstrate compliance with the air permeability standard included in the DER

Air-tightness testing:-